The present invention relates to optical networking and more particularly, in one embodiment, to reception of multiple signal types.
As service optical transport networks grow and evolve to incorporate more advanced technologies, they increasingly make use of multiple types of optical signal, rather than just one that is standardized across the network. For example, the international SDH standard provided a hierarchy of different optical signals with different data rates including 2.5 Gbps, 10 Gbps, and 40 Gbps. SONET is a North American counterpart to the SDH standard. The G.709 standard specifies another transmission standard with yet another hierarchy of transmission rates. There are also optical transmission standards based on the Gigabit Ethernet standard, such as 10 Gigabit Ethernet.
The network manager thus confronts a wide variety of optical transmission standards, and consequently a wide variety of optical transponders that are responsible for transmitting and receiving the optical signals. Unfortunately, given the inherent compatibility differences between transmission standards, a transponder of one type can only be used with signals of that type. The result is great inflexibility in network configuration. Transponders specified for one signal type can only be used with that signal type and not with other types.
Manufacturers have developed a partial solution in the form of transponders that can accommodate different signal data rates within the same client type such as SONET/SDH, G.709, Gigabit Ethernet, etc. However, manual configuration of the data rate is necessary so that the transponder properly processes the received signal and appropriately monitors signal quality.
It would be desirable to have a multi-rate, multi-client transponder that can automatically adapt to the received signal. This would provide network operators with maximum flexibility and ease of configuration.